This invention relates to a pointing device for human interaction with a computer or television display screen.
Light pens, touch pads, computer mice, touch screens, and other electromechanical and electronic pointers are used in connection with computer generated displays. Pointing with the device may be direct pointing along a line of sight to a target (as when a pointing device, such as a light pen, is directly aimed at a portion of display of a radiated or otherwise projected image) or indirect pointing (as when a mouse is manipulated to control the position of an image of a pointer on a display, without pointing the mouse itself at the display).
When the pointing device is directed to a place on an object which is being shown on an electronic display (e.g., to a command icon appearing on a CRT), the act of pointing must be linked by some sort of electronic processing to the target command icon. In the case of a mouse, the identity of the target command icon may be inferred from the location of a cursor on the display at the time of a mouse click. In the case of a light pen, the raster scanning of the display permits a one-to-one mapping of moments in time to points on the display screen so that the moment when light from the target location is detected by the pen implies the target location.
In the past, it was recognized that it would be desirable to have a direct pointing device, such as a light pen, that performs functions provided by an indirect pointing device, such as a mouse, so that the single direct pointer would perform both direct and indirect pointing device functions. However, up to now no such single device which adequately performs both functions has been developed.
Therefore, it is an object of the present invention to provide a new direct pointing device that performs mouse functions.
It is another object of the present invention to provide a system in which functions performed on a direct pointing device can be detected by a computer screen.
It is a further object of the present invention to provide a new computer screen arrangement for optically detecting function commands made on a cordless direct pointing device.
In accordance with the present invention, multiple light emitting diodes capable of emitting light at different optical wavelengths are provided in a hand held device with switches for activating the light emitting diodes separately or jointly. A matrix of radiant energy detectors are arrayed across a presentation screen at the display pixel locations of the screen. These radiant energy detectors are capable of distinguishing between the two radiant energy sources. A position location matrix is provided on the screen for detection where radiant energy is received from one or more of the radiant energy sources. Detection signal logic provides Boolean signals representative of which of the radiant energy signals are detected by the radiant energy detectors, and control function logic responds to the position information and the Boolean signals to generate a cursor on the display screen and to manipulate display objects on the screen intercepted by the cursor.